Table.FillDown

Table

Replaces null values in specified columns with the most recent non-null value above.

Syntax

Table.FillDown(table as table, columns as list) as table

Parameters

Name	Type	Required	Description
`table`	`table`	Yes	The input table containing null values to fill.
`columns`	`list`	Yes	A list of column names in which to propagate non-null values downward.

Return Value

table — The input table with null values in the specified columns replaced by the last non-null value above.

Remarks

Table.FillDown scans each specified column from top to bottom. When it encounters a null, it replaces it with the most recent non-null value from above in the same column. If the first value in a column is null, it remains null because there is no preceding value to propagate.

This function is commonly used after operations like unpivoting or when importing data where group headers appear only once and subsequent rows are blank.

Examples

Example 1: Fill down a single column

let
    Source = Table.SelectColumns(
        Table.Sort(Sales, "Region"),
        {"Region", "Product", "Quantity"}
    ),
    // Simulate a grouped export where "North" labels are missing
    WithBlanks = Table.ReplaceValue(Source, "North", null, Replacer.ReplaceValue, {"Region"})
in
    Table.FillDown(WithBlanks, {"Region"})

Result

	Region	Product	Quantity
1	East	Widget A	4
2	East	Widget C	10
3	East	Thingamajig E	1
4	East	Gadget D	1
5	East	Widget C	8
6	West	Gadget B	2
7	West	Widget A	6
8	West	Gadget B	3

Compatibility

✓ Power BI Desktop✓ Power BI Service✓ Excel Desktop✓ Excel Online✓ Dataflows✓ Fabric Notebooks